1. The Field of the Invention
This invention related to browsers and, particularly, to browsers for use on wireless devices, such as mobile phones.
2. Background and Relevant Art
Mobile browsers to enable devices such as mobile telephones to access the internet are becoming widely available. Wireless application protocol (WAP) is currently the preferred solution for authoring and accessing resources on the internet via mobile devices.
WSP is the protocol for providing resource identification for operation under the WAP protocol. With WAP, textual content is written in wireless markup language (WML), and much effort is currently being spent in order to generate content in this language. However, the generally accepted standard for internet material of a textual nature is hypertext mark up language (HTML). This means that a considerable amount of readily available content, in the form of HTML content, is not directly available to a device adapted for WML.
Attempts have been made to overcome this problem by providing mobile devices with dual mode browsers with the capability to access both WTML and HTML sites. Such an approach to the above problem does, however, introduce further problems.
Firstly, if a browser is provided both for WML and HTML then it is necessary for the user to be aware of the need to switch between the browsers as appropriate.
Furthermore, providing dual browser capability can cause problems in that within one browser the device may attempt to access a site which is in the other browser's format, continuing compatibility problems and leading to the display of illegible and confusing information to the user. This is because the Uniform Resource Identifier (URI) used to name WSP resources with the WAP protocol also use the “http:”and “https:” prefixes employed by the HTML protocol, hypertext transfer protocol (HTTP). Information for the two protocols can be found at HTTP-RFC 2616 Hypertext Transfer Protocol-HTTP/1.1 and WSP Protocol: WAP-203-WSP.
The URI of the resource does not explicitly specify which protocol data it contains and therefore which protocol should be used to access it. Accordingly, there is no ready indication to a browser employing one type of protocol that the data it has requested is not compatible with that protocol. Although some content (such as images) are suitable for access by WAP or HTTP, content authored in WML and WML Script are not.
In addition, to reduce over the air transmission of WAP content most mobile devices do not request the resource directly from the location of the resource. Instead such devices connect to a WAP gateway with the WSP protocol and informs it of the URI of the resources. The gateway then accesses the resource and converts WML and WML Script content into a binary encoding that is smaller in size. A device therefore must be able to process this encoding but does not have to process the original encoding. However, if accessed via HTTP the original encoding of the resource would be accessed and so the device would not be able to display the content. Furthermore, in such situations avoidance of connection with the gateway means that optimum use of the data reduction benefits of such protocols is not employed, delaying display of data because of the processing strain that is put on the mobile device. Additionally for security or other reasons, the content may only be available if accessed via WSP and the WAP gateway and not via HTTP, leading the user frustration when a site cannot apparently be accessed.
The present invention seeks to overcome some of the above problems.